CN112626626B

CN112626626B - One-step continuous forming and flexible deformation preparation process and equipment for polyamide 56 filaments

Info

Publication number: CN112626626B
Application number: CN202011403474.2A
Authority: CN
Inventors: 郝新敏; 郭亚飞; 闫金龙; 乔荣荣; 董梦杰
Original assignee: Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Current assignee: Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2022-07-15
Anticipated expiration: 2040-12-02
Also published as: WO2022116462A1; CN112626626A

Abstract

The invention discloses a polyamide 56 filament one-step continuous forming and flexible deformation preparation process and equipment. The one-step continuous molding and flexible deformation preparation process of the polyamide 56 filament mainly comprises three parts: the invention relates to a polyamide salt solution polymerization process, a spinning forming process and a flexible post-processing process, and the method can be used for continuously preparing Fully Drawn Yarns (FDY), Draw Textured Yarns (DTY), Air Textured Yarns (ATY) and the like in one step. The spinning process increases cooling drafting, and is favorable for obtaining the polyamide filament with stable performance and excellent quality. The method has the advantages of short flow, low energy consumption, low cost, stable product and strong functionality, and can prepare different types of polyamide filaments according to different requirements, thereby providing guidance for the industrial one-step spinning of bio-based polyamide and polyamide polymer filaments. The polyamide 56 filament prepared by the invention can be widely applied to the fields of textile industry, automobile industry, home decoration, electronic and electric appliance industry, building industry and the like.

Description

One-step continuous forming and flexible deformation preparation process and equipment for polyamide 56 filaments

Technical Field

The invention belongs to the field of textiles, and relates to a polyamide 56 filament one-step continuous forming and flexible deformation preparation process and equipment.

Background

Polyamide (PA) is an important fiber, commonly known as "nylon", the first commercial synthetic fiber product in the world, which brings substantial advantages in the end-use field: in the clothing fabric, the fabric has better moisture absorption, flexibility and drapability, and is softer in hand feeling; it has durability and pressure resistance which are difficult to be trusted in the industrial field; in terms of carpet, its abrasion resistance and lamination recovery are higher than any other fiber. In addition, the polyamide fiber final product has low initial modulus, good elastic recovery, excellent wear resistance and high fracture resistance, and can be used for preparing high-performance materials.

The production of polyamide fibres is generally carried out by the melt spinning process. Melt spinning is generally carried out by two methods, a chip melt spinning method and a melt direct spinning method. The chip spinning process includes slicing the polymer, extracting, drying and melt spinning, and has high product quality, high production flexibility and high production cost. The melt direct spinning process includes spinning polymer melt directly in a spinning machine, extruding the melt with a spinneret to form melt flow, cooling to solidify to form nascent fiber, and winding the nascent fiber on a specific spinning mechanism. In order to meet the requirements of finished fibers, a series of subsequent treatment steps such as stretching, sizing, deforming and the like are required to be carried out on the nascent fibers, the processes such as tape injection, granulation and the like are omitted, the process flow is short, energy is saved, efficiency is high, and the method has high requirements on polymerization and spinning stability.

At present, the technology of the polyamide fiber melt direct spinning process in China is not mature, and the spinning stability is poor, so the process for preparing polyamide 66 and polyamide 6 fibers in an industrial production mode mainly adopts a slice spinning method, and the process has the disadvantages of complicated steps, long time consumption and high energy consumption. Therefore, aiming at the novel bio-based polyamide 56 fiber, the development of a preparation process which is efficient and energy-saving and integrates polymerization, spinning and drafting into a whole in one step and continuous forming is urgently needed.

Disclosure of Invention

The invention aims to provide a polyamide 56 filament one-step continuous forming and flexible deformation preparation process and equipment.

The invention provides a one-step continuous forming and flexible deformation preparation process of polyamide 56 filaments, which mainly comprises three parts: the invention relates to a polyamide salt solution polymerization process, a spinning forming process and a flexible post-processing process, and the method can be used for continuously preparing Fully Drawn Yarns (FDY), Draw Textured Yarns (DTY), Air Textured Yarns (ATY) and the like in one step.

The method for preparing the polyamide 56 filament by one-step continuous forming and flexible deformation comprises a polyamide salt solution polymerization process, a spinning forming process and a flexible post-processing process;

1) the polyamide salt solution polymerization process comprises the following steps:

under the protection of nitrogen, carrying out neutralization salt-forming reaction on pentanediamine and adipic acid in water to obtain polyamide 56 salt water solution, adding an auxiliary agent into the polyamide 56 salt water solution, blending, mixing, concentrating, and carrying out prepolymerization reaction, pre-polymerization reaction and post-polymerization reaction on the concentrated salt solution to obtain a polyamide 56 polymer melt;

in the polymerization process, the nitrogen protection is three-stroke and three-row; the three flushing is the three-time nitrogen flushing; three rows of air are exhausted;

in the polymerization process, the mole ratio of the pentamethylene diamine to the adipic acid is 1-1.05: 1; specifically 1:1.01, 1:1.02, 1:1.03 and 1: 1.04;

in the polymerization process, the temperature of neutralization and salt formation is 30-50 ℃; specifically 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C; the reaction time is 30-60 min; specifically 35, 40, 45, 50 and 55 min;

in the polymerization process, the mass percentage content of the polyamide 56 saline solution is 20-80%; specifically 25, 30, 35, 40, 45, 50, 55 or 75%;

in the polymerization process, the auxiliary agent can be one or more of a molecular weight regulator, a delustering agent, a flame retardant, an antistatic agent, an antibacterial agent and the like; the addition amount of the auxiliary agent is 0.1-6% of the mass sum of the pentanediamine and the adipic acid; specifically 0.1-1 or 0.1-0.5%;

in the polymerization process, the viscosity index of the prepared polyamide 56 polymer melt is 120-160 ml/g.

In the polymerization process, the prepolymerization reaction conditions are as follows: the temperature is 210-240 ℃ (specifically 212 ℃, 217 ℃, 218 ℃, 228 ℃, 229 ℃, 238 ℃), the pressure is 1.70-1.85 MPa (specifically 1.73, 1.75, 1.78, 1.8, 1.82MPa), and the pressure holding time is 30-180 min (specifically 90, 100, 120, 150, 160 min); after the reaction is finished, quickly flashing and decompressing, and heating to 270-290 ℃ (278 ℃, 285 ℃ and 286 ℃); conditions of the pre-polymerization reaction: the temperature is 270 ℃ to 290 ℃ (278 ℃, 285 ℃ and 286 ℃) and the reaction time is 20min to 150min (specifically 50, 60, 80, 90 or 100 min); post-polymerization conditions: the temperature is 270-290 ℃ (specifically 278 ℃, 280 ℃ or 288 ℃), the vacuum degree is 0.2-0.3 MPa (specifically 0.21, 0.25, 0.26 or 0.28MPa), the reaction time is 10-150 min (specifically 15, 30, 40, 50 or 60min), and the water in the system is discharged, so that the polyamide 56 polymer melt is obtained;

2) the spinning forming process comprises the following steps:

extruding the polyamide 56 polymer melt prepared in the step 1) by a screw, spraying the extruded melt by a spinneret plate to obtain melt trickle, cooling and blowing the melt trickle to solidify the melt trickle into strand silk, winding and oiling the strand silk, performing cold and hot drafting, and performing heat setting to obtain polyamide 56 filament bundles;

in the spinning and forming step, the temperatures of all zones of the screw are as follows in sequence: the first zone temperature is 260-300 ℃ (specifically 260 ℃, 265 ℃, 270 ℃, 275 ℃, 278 ℃, 288 ℃, or 298 ℃), the second zone temperature is 260-300 ℃ (specifically 260 ℃, 265 ℃, 270 ℃, 275 ℃, 278 ℃, 288 ℃, or 298 ℃), the third zone temperature is 250-295 ℃ (specifically 255 ℃, 260 ℃, 265 ℃, 275 ℃, 278 ℃, 288 ℃, or 298 ℃), the fourth zone temperature is 250-295 ℃ (specifically 255 ℃, 260 ℃, 265 ℃, 270 ℃, 275 ℃, 278 ℃, 288 ℃, or 298 ℃), the fifth zone temperature is 250-290 ℃ (specifically 255 ℃, 260 ℃, 265 ℃, 270 ℃, 275 ℃, 278 ℃, 288 ℃, or 298 ℃), and the sixth zone temperature is 250-290 ℃ (specifically 255 ℃, 260 ℃, 265 ℃, 270 ℃, 278 ℃, 288 ℃, or 298 ℃);

the rotating speed of the screw is 50-100 r/min; specifically 55, 65, 70, 75, 80, 85, 90 or 95 r/min;

the temperature of the spinning beam is 270-290 ℃ (specifically 270 ℃, 275 ℃, 278 ℃, 280 ℃, 285 ℃ or 288 ℃);

the cooling blowing is a cross blowing process or a circular blowing process, and the process conditions are as follows: the wind speed can be 0.30-0.80 m/min; the wind temperature can be 18-25 ℃ (specifically 18, 19, 20, 22 or 24 ℃); the wind pressure can be 350-500 Pa (specifically 350, 380, 400, 450 or 480 Pa);

in the oiling step, the amount of oil fed by a pump is controlled to be 0.3-0.5% of the titer of the product; specifically, it can be 0.4%;

in the spinning forming process, the spinning speed is 3000-5000 m/min; specifically 3500, 4000, 4500, 3800 or 4800 m/min;

the step of drawing comprises the steps of cold drawing and hot drawing;

the cold drawing multiplying power is 1.01-1.50 (specifically 1.02, 1.03, 1.2, 1.3, 1.4 or 1.5), the temperature is 0-20 ℃, and the primary drawing is performed;

the hot stretching multiplying power is 3.00-5.50 (specifically 3.5, 4.0, 4.5, 4.8), the temperature is 100-210 ℃ (specifically 150, 180, 190, 200, 208, 215 ℃), and the first-stage stretching, the second-stage stretching or the multistage stretching can be carried out;

the setting temperature is 130-200 ℃ (specifically 135, 140, 145, 150, 155, 165, 178, 170, 188 or 190 ℃), and the setting time is 1-5 min (specifically 1, 2, 3, 4 or 5 min);

3) the flexible post-processing technology comprises the following steps:

the flexible post-processing is to prepare polyamide 56 filaments with different styles according to different requirements of the market on products;

if the polyamide 56 Fully Drawn Yarn (FDY) is required to be prepared, the prepared and molded polyamide 56 filament bundle in the step 2) needs to be subjected to post-processing processes of hot drawing, heat setting and winding in sequence;

in the flexible post-processing step, the process conditions for preparing the fully drawn yarn are as follows: the hot drawing process can be primary drawing, secondary drawing or multi-stage drawing, the temperature is 100-230 ℃ (specifically 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 165, 178, 170, 188, 190 ℃, 200, 210 or 220 ℃), the drawing multiple is 1.01-2.00 (specifically 1.02, 1.03, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or 1.9), and the speed of the drawing roller is 500-1500 m/min (specifically 800, 900, 1000, 1100, 1200 or 1450 m/min); the heat setting temperature is 150-200 deg.C (preferably 155, 165, 178, 170, 188 or 190 deg.C); the winding speed is 1000-1500 m/min (specifically 1100, 1150, 1200, 1250 or 1450 m/min);

if the polyamide 56 Draw Textured Yarn (DTY) is required to be prepared, the polyamide 56 filament bundle prepared and molded in the step 2) needs to be sequentially subjected to post-processing processes of hot drawing, twisting, networking, heat setting, oiling and winding;

in the flexible post-processing step, the process conditions for preparing the tensile textured yarn are as follows: the hot drawing process may be primary drawing, secondary drawing or multi-stage drawing, the temperature is 100-200 ℃ (specifically 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 165, 178, 170, 188 or 190 ℃), the drawing multiple is 1.01-2.00 (specifically 1.02, 1.03, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or 1.9), the drawing roller speed is 300-1000 m/min (specifically 400, 500, 600, 700, 800, 900 or 950m/min), the twisting is divided into S twist or Z twist, the tension twisting is 20-60 cN (specifically 25, 30, 35, 40, 45, 50 or 55cN), and the release tension is 25-65 cN (specifically 25, 30, 35, 40, 45, 50, 55 or 60 cN); the D/Y is the ratio of the surface speed of the friction disc to the speed of the strand leaving the false twister, and is specifically 1.5-2.0; in the network step, the wind pressure is 1.0-1.6 bar; the diameter of the nozzle is 1.2-1.6 mm, the heat setting temperature is 180-220 ℃ (188, 190, 195, 200, 210 or 215 ℃), and the winding speed is 600-1200 m/min (650, 700, 750, 800, 850, 900, 950, 1000, 1100 or 1150 m/min).

If the preparation of the polyamide 56 Air Textured Yarn (ATY) is required, the prepared and formed polyamide 56 filament bundle in the step 2) needs to be subjected to post-processing processes of hot drawing, thermal spraying deformation, cooling stabilization and winding in sequence;

in the flexible post-processing step, the process conditions for preparing the air textured yarn are as follows: the hot drawing process can be primary drawing, secondary drawing or multistage drawing, the temperature is 100-190 ℃, the drawing multiple is 1.01-2.00 (specifically 1.02, 1.03, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or 1.9), the speed of a drawing roller is 1500-2500 m/min (specifically 1600, 1650, 1700, 1750, 1800, 1900, 2000, 2100, 2200, 2300 or 2450 m/min); the hot-spraying deformation air temperature is 190-230 ℃ (specifically 195, 200, 210, 215, 220 or 225 ℃), the air spraying pressure is 195-550 kPa (specifically 200, 300, 350, 400, 450, 500kPa), the overfeeding rate is 15-30% (specifically 18, 20, 25 or 28%), the cooling air temperature is 15-30 ℃ (specifically 18, 20, 25 or 28 ℃), and the winding speed is 1500-2800 m/min (specifically 1600, 1650, 1700, 1750, 1800, 1900, 2000, 2100, 2200, 2300, 2450, 2500, 2600, 2700 or 2750 m/min).

The equipment used in the method for preparing the polyamide 56 filaments by one-step continuous forming consists of a polymerization reaction device, a spinning forming device and a flexible post-processing device, wherein the polymerization reaction device is connected with the spinning forming device to directly prepare the polyamide 56 ultra-high-speed filaments; then according to different requirements of the market on products, connecting a flexible post-processing device, thereby preparing polyamide 56 filaments with different styles;

the flexible post-processing device connected behind the spinning forming device comprises a Fully Drawn Yarn (FDY) preparation device, a Draw Textured Yarn (DTY) preparation device, an Air Textured Yarn (ATY) preparation device and the like;

the polymerization reaction device consists of a raw material kettle, a salt forming kettle (used for mixing two raw materials of pentanediamine and adipic acid in the kettle to generate neutralization reaction), a salt solution storage tank, a salt solution blending tank, a salt solution intermediate tank, a concentration tank, a U-shaped reactor, a flash evaporator, a front polymerizer and a rear polymerizer which are connected in sequence;

specifically, the number of the raw material kettles is two, namely a pentanediamine raw material kettle and an adipic acid raw material kettle;

the spinning forming device consists of a spinning box body with a spinneret plate, a spinning channel through which melt trickle generated by the spinning box body flows, a blowing device for blowing the melt trickle, a device for bundling and oiling the melt trickle after blowing, and a cold and hot drafting device;

the flexible post-processing device is any one of the following flexible post-processing devices a-c:

the flexible post-processing device Fully Drawn Yarn (FDY) preparation device a consists of a drawing roller, a shaping device and a winding device which are connected in sequence;

the flexible post-processing device Draw Textured Yarn (DTY) preparation device b consists of a drawing roller, a false twisting device, a network device, a shaping device, an oiling device and a winding device which are connected in sequence;

the flexible post-processing device Air Textured Yarn (ATY) preparation device c is composed of a drawing roller, a cooling device, a jet texturing device and a winding device which are connected in sequence and is used for preparing an air textured yarn process device.

In the flexible post-processing, the shaping device is a hot plate or a hot box.

Specifically, the linear density of the polyamide 56 filaments is 1-7 dtex; the breaking strength is 3-12 cN/dtex, the flame retardant property is achieved, and the limiting oxygen index is not less than 32%.

According to the one-step continuous forming and flexible deformation preparation process and equipment for the polyamide 56 filaments, a cooling and drafting process is added in a spinning process, and the reason that the cooling and crystallization rate of the polyamide 56 is low in research, the incompletely cooled filament bundle influences a winding and oiling process, and various properties of a product prepared by directly post-processing are unstable, so that the filament bundle formed by a spinneret plate is rapidly cooled by adding the cooling and drafting process, molecular chains are rapidly accumulated, and crystallization is incomplete, and the polyamide 56 filaments with stable properties and excellent quality can be obtained by drafting and shaping at high temperature subsequently. The method has the advantages of short flow, low energy consumption, low cost, stable product and strong functionality, and can prepare different types of polyamide filaments according to different requirements, thereby providing guidance for the industrial one-step spinning of bio-based polyamide and polyamide polymer filaments. The polyamide 56 filament prepared by the invention can be widely applied to the fields of textile industry, automobile industry, home decoration, electronic and electric appliance industry, building industry and the like.

Drawings

FIG. 1 shows a polymerization and spinning apparatus; 1. a raw material kettle; 2. a salt forming kettle; 3. a salt solution storage tank; 4. a salt solution preparation tank; 5. a salt solution intermediate tank; 6. a concentration tank; 7. a U-shaped reactor; 8. a flash evaporator; 9. a pre-polymerizer; 10. a post-polymerizer; 11. spinning manifold; 12. a blowing device; 13. a spinning channel; 14. a cluster oiling device; 15. a winding device; 16. a cold drawing device; 17. a hot drawing device; 18. a shaping device;

FIG. 2 is a flexible post-processing apparatus for preparing Fully Drawn Yarn (FDY); 17. a hot drawing device; 18. a shaping device; 22. and (4) a winding device.

FIG. 3 is a flexible post-processing apparatus for making Draw Textured Yarns (DTY); 17. a hot drawing device; 19. a false twisting device; 20. a network device; 18. a shaping device; 21. an oiling device; 22. and (4) a winding device.

FIG. 4 is a flexible post-processing apparatus used to make Air Textured Yarns (ATY); 17. a hot drawing device; 23. a thermal spray deformation device; 24. cooling device, 22, coiling device.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified. The following examples, samples of polyamide 56 filaments, the properties of which were measured according to the following methods:

1. breaking strength, elongation at break: GB/T14344-;

2. moisture regain: GB/T6503-2017 chemical fiber moisture regain test method;

3. limiting oxygen index: GB/T5454-1997 textile flammability test oxygen index method;

4. melting point: the test is carried out by adopting a Q2000 type differential scanning calorimeter of the American TA company, and the temperature is increased from room temperature to 300 ℃ at the speed of 10 ℃/min under the protection of nitrogen;

5. antibacterial property: GB/T20944.3-2008 is an oscillation method for evaluating the antibacterial performance of textiles.

Examples 1,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.01: 1 in water, reacting at 40 ℃ for 50min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Under the protection of nitrogen, adding polyamide 56 salt aqueous solution into a salt solution preparation tank, adding 0.5% of auxiliary agent pentamethylene diamine into the salt solution preparation tank, adjusting the pH value of the salt solution to 7.73, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 120min at the temperature of 210 ℃ and the pressure of 1.70MPa, carrying out prepolymerization reaction, after the prepolymerization reaction is finished, rapidly decompressing in a flash evaporator, heating to 280 ℃, entering a pre-polymerizer, keeping the temperature at 280 ℃ for 90min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at the temperature of 280 ℃ and the vacuum degree of 0.25MPa, carrying out polymerization reaction for 50min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 70r/min, the spinning speed is 4350m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 278 ℃, the temperature of the second zone is 281 ℃, the temperature of the third zone is 283 ℃, the temperature of the fourth zone is 283 ℃, the temperature of the fifth zone is 283 ℃, and the temperature of the sixth zone is 283 ℃; the temperature of a spinning box body is 285 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt thin flow, the melt thin flow is blown by air on the side to be cooled and solidified into strand silk, and the cooling air speed is 0.6 m/min; the air temperature is 21 ℃, the air pressure can be 400Pa, the cooled strand silk is oiled, the oil quantity applied by a pump is controlled to be 0.3 percent of the titer of the product, and then the polyamide 56 tows are obtained by cold drawing at 10 ℃ by 1.10 times, drawing at 145 ℃ by 3.54 times and shaping at 155 ℃ for 1 min;

the tows are drafted by 1.50 times at 170 ℃, the speed of a final drafting roller is 1200m/min, heat setting is carried out at 180 ℃, and the tows are wound at 1300m/min to form the polyamide 56 fully-drawn yarn.

The detection result of the fully drawn yarn performance is as follows: the breaking strength is 4.93cN/dtex, the elongation at break is 38.2%, the moisture regain is 4.12%, the melting point is 253.3 ℃, and the limiting oxygen index is 33.2%.

Examples 2,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.02: 1 in water, reacting at 50 ℃ for 40min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Adding polyamide 56 salt aqueous solution into a salt solution preparation tank under the protection of nitrogen, adding 2.5% of titanium dioxide serving as a flatting agent into the salt solution preparation tank, adjusting the pH value of the salt solution to 7.86, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 100min at the temperature of 218 ℃ and the pressure of 1.73MPa, carrying out prepolymerization reaction, after the prepolymerization reaction is finished, rapidly decompressing in a flash evaporator, heating to 278 ℃, entering a pre-polymerizer, keeping the temperature at 278 ℃ for 60min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at the temperature of 278 ℃ and the vacuum degree of 0.21MPa, carrying out polymerization reaction for 40min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 65r/min, the spinning speed is 3180m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 290 ℃, the temperature of the second zone is 290 ℃, the temperature of the third zone is 290 ℃, the temperature of the fourth zone is 290 ℃, the temperature of the fifth zone is 290 ℃ and the temperature of the sixth zone is 290 ℃; the temperature of a spinning box body is 290 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt thin flow, the melt thin flow is blown by air on the side to be cooled and solidified into filaments, and the cooling air speed is 0.8 m/min; the air temperature is 25 ℃, the air pressure can be 480Pa, the cooled strand silk is oiled, the oil loading amount is controlled to be 0.35 percent of the titer of the product by a pump, and then the cooled strand silk is subjected to cold drawing at 5 ℃ for 1.13 times, drawing at 150 ℃ for 3.32 times and shaping at 160 ℃ for 1min to obtain polyamide 56 tows;

the tows are drafted by 1.71 times at 190 ℃, the speed of a final drafting roller is 800m/min, heat setting is carried out at 190 ℃, and the tows are wound at 900m/min to form the polyamide 56 fully-drawn yarn.

The detection result of the fully drawn yarn performance is as follows: the breaking strength is 5.86cN/dtex, the elongation at break is 32.8%, the moisture regain is 4.08%, the melting point is 253.9 ℃, and the limiting oxygen index is 34.4%.

Examples 3,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.05: 1 in water, reacting at 60 ℃ for 30min, and stirring until the polyamide 56 salt is completely dissolved to obtain the polyamide 56 salt aqueous solution. Under the protection of nitrogen, adding polyamide 56 salt water solution into a salt solution preparation tank, adding 6% of flame retardant TL into the salt solution preparation tank, adjusting the pH value of the salt solution to 7.81, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 90min at the temperature of 228 ℃ and the pressure of 1.75MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 283 ℃, entering a pre-polymerizer, keeping the temperature at 283 ℃ for 50min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at the temperature of 283 ℃ and the vacuum degree of 0.25MPa, carrying out polymerization reaction for 40min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 85r/min, the spinning speed is 3710m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 265 ℃, the temperature of the second zone is 265 ℃, the temperature of the third zone is 265 ℃, the temperature of the fourth zone is 265 ℃, the temperature of the fifth zone is 265 ℃, and the temperature of the sixth zone is 265 ℃; the temperature of a spinning box body is 265 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt trickle, the melt trickle is cooled and solidified into strand silk by side air blowing, and the cooling air speed is 0.4 m/min; the air temperature is 21 ℃, the air pressure can be 380Pa, the cooled strand silk is oiled, the oil adding amount is controlled by the pump supply amount to be 0.4 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 0 ℃ for 1.06 times, drawing at 160 ℃ for 3.41 times and sizing at 170 ℃ for 1min to obtain polyamide 56 tows;

the filament bundle is drafted 1.51 times at 190 ℃, the speed of a final drafting roller is 1000m/min, heat setting is carried out at 200 ℃, and the filament bundle is wound at 1100m/min to form the polyamide 56 fully drawn yarn.

The detection result of the fully drawn yarn performance is as follows: the breaking strength is 4.71cN/dtex, the elongation at break is 39.6%, the moisture regain is 4.07%, the melting point is 252.8 ℃, and the limiting oxygen index is 35.7%.

Examples 4,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.02: 1 in water, reacting at 50 ℃ for 35min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Under the protection of nitrogen, adding polyamide 56 salt water solution into a salt solution preparation tank, adding 2% of antibacterial agent KS-116 into the salt solution preparation tank, adjusting the pH value of the salt solution to 7.86, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 100min at 229 ℃ and 1.75MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 280 ℃, entering a pre-polymerizer, keeping the temperature at 280 ℃ for 60min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at 280 ℃ and under the vacuum degree of 0.25MPa, carrying out polymerization reaction for 30min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 75r/min, the spinning speed is 3450m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 276 ℃, the temperature of the second zone is 276 ℃, the temperature of the third zone is 276 ℃, the temperature of the fourth zone is 276 ℃, the temperature of the fifth zone is 276 ℃, and the temperature of the sixth zone is 276 ℃; the temperature of a spinning box body is 276 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt trickle, the melt trickle is cooled and solidified into strand silk by side air blowing, and the cooling air speed is 0.4 m/min; the air temperature is 20 ℃, the air pressure can be 400Pa, the cooled strand silk is oiled, the oil adding amount is controlled by a pump to be 0.4 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 10 ℃ for 1.10 times, drawing at 165 ℃ for 3.51 times and shaping at 175 ℃ for 1min to obtain polyamide 56 tows;

the filament bundle is subjected to drafting by 1.30 times at 190 ℃, the speed of a final drafting roller is 1000m/min, heat setting is carried out at 200 ℃, and the filament bundle is wound at 1100m/min to form the polyamide 56 fully drawn yarn.

The detection result of the fully drawn yarn performance is as follows: the breaking strength is 4.66cN/dtex, the elongation at break is 40.6%, the moisture regain is 4.01%, the melting point is 252.0 ℃, the limiting oxygen index is 35.5%, and the fiber bacteriostasis rate is 91.2%.

Examples 5,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.03: 1 in water, reacting at 40 ℃ for 45min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Adding polyamide 56 salt water solution into a salt solution preparation tank under the protection of nitrogen, fully mixing, adjusting the pH value of the salt solution to 7.83, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 150min at 217 ℃ and 1.75MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 285 ℃, entering a pre-polymerizer, keeping the temperature at 285 ℃ for 80min, allowing the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at 285 ℃ and under the vacuum degree of 0.25MPa, performing polymerization reaction for 60min, discharging water in the system, and finishing the polymerization reaction to obtain a polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 60r/min, the spinning speed is 3200m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 282 ℃, the temperature of the second zone is 285 ℃, the temperature of the third zone is 285 ℃, the temperature of the fourth zone is 285 ℃, the temperature of the fifth zone is 285 ℃, and the temperature of the sixth zone is 285 ℃; the temperature of a spinning box body is 286 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt trickle, the melt trickle is cooled and solidified into strand silk by side air blowing, and the cooling air speed is 0.5 m/min; the air temperature is 20 ℃, the air pressure can be 430Pa, the cooled strand silk is oiled, the oil loading amount is controlled to be 0.3 percent of the titer of the product by a pump, and then the polyamide 56 tows are obtained by cold drawing at 10 ℃ by 1.10 times, drawing at 150 ℃ by 3.11 times and shaping at 155 ℃ for 1 min;

drafting polyamide 56 tows at 170 ℃ by 1.15 times, wherein the speed of a final drafting roller is 800m/min, Z twisting, twisting tension 33cN and untwisting tension 37 cN; D/Y is 1.5; the network wind pressure is 1.0 bar; the diameter of the nozzle was 1.2mm, heat-set at 180 ℃ and wound at a speed of 1000m/min to obtain a polyamide 56 drawn textured yarn.

The detection result of the tensile deformation silk performance is as follows: the breaking strength is 4.34cN/dtex, the elongation at break is 44.7%, the moisture regain is 4.76%, the melting point is 252.5 ℃, and the limiting oxygen index is 35.5%.

Examples 6,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.03: 1 in water, reacting at 30 ℃ for 50min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Adding 3% of flame retardant TL-012 salt solution into polyamide 56 salt solution under the protection of nitrogen, fully mixing, adjusting the pH value of the salt solution to 7.85, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 150min at the temperature of 228 ℃ and the pressure of 1.78MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 286 ℃, entering a pre-polymerizer, keeping the temperature at 286 ℃ for 90min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at the temperature of 286 ℃ and the vacuum degree of 0.26MPa, carrying out polymerization reaction for 50min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 75r/min, the spinning speed is 3450m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 282 ℃, the temperature of the second zone is 282 ℃, the temperature of the third zone is 282 ℃, the temperature of the fourth zone is 282 ℃, the temperature of the fifth zone is 282 ℃ and the temperature of the sixth zone is 282 ℃; the temperature of a spinning box body is 283 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt thin flow, the melt thin flow is blown by air on the side to be cooled and solidified into strand wires, and the cooling air speed is 0.3 m/min; the air temperature is 20 ℃, the air pressure can be 460Pa, the cooled strand silk is oiled, the oil loading amount is controlled by the pump supply amount to be 0.4 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 3 ℃ for 1.18 times, drawing at 120 ℃ for 3.20 times and sizing at 130 ℃ for 2min to obtain polyamide 56 tows;

drafting polyamide 56 tows at 160 ℃ by 1.31 times, wherein the speed of a final drafting roller is 1000m/min, S twisting, twisting tension 20cN and untwisting tension 25 cN; D/Y is 1.6; the network wind pressure is 1.2 bar; the diameter of the nozzle was 1.3mm, heat-set at 180 ℃ and wound at a speed of 1000m/min to obtain a polyamide 56 drawn textured yarn.

And (3) tensile deformation silk performance detection results: the breaking strength is 4.64cN/dtex, the elongation at break is 32.6%, the moisture regain is 4.46%, the melting point is 252.1 ℃, and the limiting oxygen index is 35.7%.

Example 7,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.02: 1 in water, reacting at 45 ℃ for 40min, and stirring until the polyamide 56 salt is completely dissolved to obtain the polyamide 56 salt aqueous solution. Under the protection of nitrogen, adding a 3% antibacterial agent KS-116 salt solution into a polyamide 56 salt water solution, fully mixing, adjusting the pH value of the salt solution to 7.80, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 150min at the temperature of 212 ℃ and the pressure of 1.82MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 283 ℃, entering a pre-polymerizer, keeping the temperature at 283 ℃ for 100min, allowing the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at 283 ℃ and under the vacuum degree of 0.28MPa, performing polymerization reaction for 30min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 83r/min, the spinning speed is 4150m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 287 ℃, the temperature of the second zone is 287 ℃, the temperature of the third zone is 287 ℃, the temperature of the fourth zone is 287 ℃, the temperature of the fifth zone is 287 ℃, and the temperature of the sixth zone is 287 ℃; the temperature of a spinning box body is 287 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt thin flow, the melt thin flow is blown by air on the side to be cooled and solidified into thread strips, and the cooling air speed is 0.4 m/min; the air temperature is 22 ℃, the air pressure can be 420Pa, the cooled strand silk is oiled, the oil adding amount is controlled by the pump supply amount to be 0.4 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 8 ℃ for 1.24 times, drawing at 145 ℃ for 3.25 times and shaping at 155 ℃ for 1.5min to obtain polyamide 56 tows;

drafting the polyamide 56 tows by 1.46 times at 190 ℃, wherein the speed of a final drafting roller is 900m/min, S twist, twisting tension 40cN and untwisting tension 45 cN; D/Y is 1.8; the network wind pressure is 1.3 bar; the nozzle diameter was 1.6mm, heat-set at 200 ℃ and wound at a speed of 1000m/min to obtain a polyamide 56 drawn textured yarn.

The detection result of the tensile deformation silk performance is as follows: breaking strength of 5.04cN/dtex, elongation at break of 32.5%, moisture regain of 4.16%, melting point of 252.5 ℃, limiting oxygen index of 33.7%, and antibacterial rate of 93.3%

Example 8,

Mixing pentanediamine and adipic acid according to the weight ratio of 1.05: 1 in water, reacting at 45 ℃ for 40min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Adding polyamide 56 salt water solution into a salt solution preparation tank under the protection of nitrogen, fully mixing, adjusting the pH value of the salt solution to 7.86, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 180min at the temperature of 238 ℃ and the pressure of 1.85MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 288 ℃, entering a pre-polymerizer, keeping the temperature at 288 ℃ for 50min, enabling the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at the temperature of 288 ℃ and the vacuum degree of 0.28MPa, carrying out polymerization reaction for 15min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 80r/min, the spinning speed is 3600m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 290 ℃, the temperature of the second zone is 290 ℃, the temperature of the third zone is 290 ℃, the temperature of the fourth zone is 290 ℃, the temperature of the fifth zone is 290 ℃ and the temperature of the sixth zone is 290 ℃; the temperature of a spinning box body is 290 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt trickle, the melt trickle is cooled and solidified into strand silk by side air blowing, and the cooling air speed is 0.5 m/min; the air temperature is 20 ℃, the air pressure can be 450Pa, the cooled strand silk is oiled, the oil adding amount is controlled by the pump supply amount to be 0.3 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 10 ℃ for 1.14 times, drawing at 150 ℃ for 3.83 times and sizing at 155 ℃ for 1min to obtain polyamide 56 tows;

the polyamide 56 filament bundle is drafted by 1.31 times at 165 ℃, the speed of a final drafting roller is 2000m/min, hot air is sprayed at 210 ℃ for deformation, the air spraying pressure is 280kPa, the overfeed rate is 18 percent, the air is cooled at 15 ℃, and then the polyamide 56 air textured filament is obtained by winding at 2000 m/min.

Air textured yarn performance detection results: the breaking strength is 5.11cN/dtex, the elongation at break is 20.2%, the moisture regain is 4.18%, the melting point is 251.7 ℃, and the limiting oxygen index is 33.4%.

Examples 9,

Pentamethylene diamine and adipic acid were mixed in a ratio of 1.04: 1 in water, reacting at 50 ℃ for 35min, and stirring until the polyamide 56 is completely dissolved to obtain a polyamide 56 salt aqueous solution. Under the protection of nitrogen, adding a 4% flame retardant FR-310 salt solution into a polyamide 56 salt solution, fully mixing, adjusting the pH value of the salt solution to 7.84, and concentrating the mixed salt solution;

injecting the concentrated salt solution into a U-shaped reactor, starting prepolymerization reaction, maintaining the pressure for 160min at 230 ℃ and under the pressure of 1.80MPa for prepolymerization reaction, after the prepolymerization reaction is finished, quickly decompressing in a flash evaporator, heating to 286 ℃, entering a pre-polymerizer, keeping the temperature at 286 ℃ for 100min, allowing the polymerization degree to be close to a finished product, entering a post-polymerizer, stirring at 286 ℃ and under the vacuum degree of 0.3MPa, performing polymerization reaction for 40min, discharging water in the system, and finishing the polymerization reaction to obtain the polyamide 56 polymer melt.

Extruding the polyamide 56 polymer melt by a screw, wherein the rotating speed of the screw is 80r/min, the spinning speed is 3200m/min, and the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 293 ℃, the temperature of the second zone is 293 ℃, the temperature of the third zone is 293 ℃, the temperature of the fourth zone is 293 ℃, the temperature of the fifth zone is 293 ℃, and the temperature of the sixth zone is 293 ℃; the temperature of a spinning box body is 293 ℃, a polymer is extruded by a screw rod and is sprayed out by a spinneret plate to obtain melt thin flow, the melt thin flow is blown by air on the side to be cooled and solidified into filaments, and the cooling air speed is 0.8 m/min; the air temperature is 18 ℃, the air pressure can be 480Pa, the cooled strand silk is oiled, the oil quantity applied by a pump is controlled to be 0.5 percent of the titer of the product, and then the cooled strand silk is subjected to cold drawing at 0 ℃ by 1.08 times, drawing at 155 ℃ by 4.14 times and sizing at 165 ℃ for 1min to obtain polyamide 56 tows;

the polyamide 56 filament bundle is drafted by 1.18 times at 170 ℃, the speed of a final drafting roller is 1800m/min, hot air jet texturing is carried out at 190 ℃, the air jet pressure is 350kPa, the overfeed rate is 20 percent, air cooling is carried out at 18 ℃, and then winding is carried out at 2000m/min to obtain the polyamide 56 air textured yarn.

Air textured yarn performance test results: the breaking strength is 5.05cN/dtex, the elongation at break is 31.7 percent, the moisture regain is 4.20 percent, the melting point is 252.1 ℃, and the limiting oxygen index is 36.8 percent.

Comparative example 1

The preparation of the salt solution of polyamide 56 and the polymer at the early stage is completely the same as that in the embodiment 1, when the polymer melt is sprayed out by a screw extruder and a spinneret plate of a spinning manifold to obtain melt trickle, the melt trickle is cooled and solidified into filaments by a side blowing device, the filaments are oiled and then are directly subjected to post-processing technologies such as bundling and the like (the process parameters are set according to the embodiment 1 of the invention) according to the traditional spinning processing to prepare different types of filaments.

The test result shows that the polyimide 56 filament prepared by the process has poor performance, more broken filaments, no winding of partial filaments, easy barrel explosion and no forming, because the cooling speed of the polyamide 56 is lower than that of the polyamide 66, the temperature of the filament before winding is still high, the filament can not radiate heat in time during high-speed winding, so that the fuse phenomenon can occur, and even the barrel explosion can occur due to overhigh temperature. Under the experimental condition, the performance of the winding-formed filament is tested, the breaking strength is only 0.5-2.0 cN/dtex, the limiting oxygen index is 20-24%, the filament prepared by the process has low strength, no flame resistance, and various performances are unstable, and cannot reach the application standard.

Claims

1. A preparation method of polyamide 56 filament by one-step continuous forming and flexible deformation is characterized by comprising the following steps: the method comprises a polyamide salt solution polymerization process, a spinning forming process and a flexible post-processing process:

2) the spinning forming process comprises the following steps:

the cold and hot drawing step comprises cold drawing and hot drawing steps;

in the cold drawing step, the cold drawing multiplying power is 1.01-1.50; the temperature is 0-20 ℃; primary drawing;

in the hot drawing step, the hot drawing multiplying power is 3.00-5.50; the temperature is 100-210 ℃; primary drawing, secondary drawing or multi-stage drawing;

3) the flexible post-processing technology comprises the following steps:

when preparing polyamide 56 Fully Drawn Yarn (FDY), the polyamide 56 filament bundle prepared and molded in the step 2) needs to be subjected to post-processing processes of hot drawing, heat setting and winding in sequence;

when preparing polyamide 56 Draw Textured Yarn (DTY), the prepared and molded polyamide 56 filament bundle in the step 2) needs to be sequentially subjected to post-processing processes of hot drawing, twisting, meshing, heat setting, oiling and winding;

when preparing the polyamide 56 Air Textured Yarn (ATY), the prepared and molded polyamide 56 filament bundle in the step 2) needs to be subjected to post-processing processes of hot drawing, thermal spraying deformation, cooling stabilization and winding in sequence;

the linear density of the polyamide 56 filaments is 1-7 dtex; the breaking strength is 3-12 cN/dtex, the flame retardance is realized, and the limiting oxygen index is more than or equal to 32%.

2. The method of claim 1, wherein: in the step 1), nitrogen protection is performed by three-flushing three-row; the three flushing is the three-time nitrogen flushing; three rows of air are exhausted;

the mole ratio of the pentamethylene diamine to the adipic acid is 1-1.05: 1;

the temperature of the neutralization and salt formation reaction is 30-50 ℃; the reaction time is 30-60 min;

the mass percentage content of the polyamide 56 saline solution is 20-80%;

the auxiliary agent is at least one of a molecular weight regulator, a delustering agent, a flame retardant, an antistatic agent and an antibacterial agent;

the addition amount of the auxiliary agent is 0.1-6% of the mass sum of the pentanediamine and the adipic acid;

the viscosity index of the polyamide 56 polymer melt is 120-160 ml/g.

3. The method according to claim 1 or 2, characterized in that: in the step 1), the prepolymerization reaction conditions are as follows: the temperature is 210-240 ℃, the pressure is 1.7-1.85 MPa, and the pressure maintaining time is 30-180 min; after the reaction is finished, quickly flashing and decompressing, and heating to 270-290 ℃;

the conditions of the pre-polymerization reaction are as follows: the temperature is 270-290 ℃, and the reaction time is 20-150 min;

the conditions for the postpolymerization are as follows: the temperature is 270-290 ℃, the vacuum degree is 0.2-0.3 MPa, the reaction time is 10-150 min, and the water in the system is discharged.

4. The method according to claim 1 or 2, characterized in that: in the step 2) of spinning and forming, the temperatures of all zones of the screw are as follows in sequence: the temperature of the first zone is 260-300 ℃, the temperature of the second zone is 260-300 ℃, the temperature of the third zone is 250-295 ℃, the temperature of the fourth zone is 250-295 ℃, the temperature of the fifth zone is 250-290 ℃, and the temperature of the sixth zone is 250-290 ℃;

the rotating speed of the screw is 50-100 r/min;

the temperature of the spinning box body is 270-290 ℃;

the cooling air blowing is a side air blowing process or a circular air blowing process;

in the oiling step, the oil feeding amount is controlled by a pump to be 0.3% -0.5% of the titer of the product;

in the steps, the spinning speed is 3000-5000 m/min;

in the heat setting step, the temperature is 130-200 ℃; the setting time is 1-5 min.

5. The method of claim 4, wherein: the wind speed of the cooling air blower is 0.30-0.80 m/min; the air temperature is 18-25 ℃; the wind pressure is 350-500 Pa.

6. The method according to claim 1 or 2, characterized in that: in the step 3), when the polyamide 56 filament is Fully Drawn Yarn (FDY), the process conditions are as follows: the drafting is primary drafting, secondary drafting or multistage drafting, the temperature is 100-230 ℃, the drafting multiple is 1.01-2.00, the speed of a final drafting roller is 500-1500 m/min, and the heat setting temperature is 150-200 ℃; the winding speed is 1000-1500 m/min.

7. The method according to claim 1 or 2, characterized in that: in the step 3), when the polyamide 56 filament is a Draw Textured Yarn (DTY), the process conditions are as follows: the drafting is primary drafting, secondary drafting or multi-stage drafting, the temperature is 100-200 ℃, the drafting multiple is 1.10-2.50, and the speed of a final drafting roller is 300-1000 m/min; twisting is divided into S twisting or Z twisting, twisting tension is 20-60 cN, and untwisting tension is 25-65 cN; D/Y is the ratio of the surface speed of the friction disc to the speed of the yarn leaving the false twister, and is specifically 1.5 to 2.0; in the network step, the wind pressure is 1.0-1.6 bar; the diameter of the nozzle is 1.2-1.6 mm; the heat setting temperature is 180-220 ℃; the winding speed is 600-1200 m/min.

8. The method according to claim 1 or 2, characterized in that: in the step 3), when the polyamide 56 filament is an Air Textured Yarn (ATY), the process conditions are as follows: the drafting is primary drafting, secondary drafting or multistage drafting, the temperature is 100-190 ℃, the drafting multiple is 1.01-2.00, and the speed of a final drafting roller is 1500-2500 m/min; the temperature of hot spraying deformation air is 190-230 ℃, the air spraying pressure is 195-550 kPa, the overfeed rate is 15-30%, the temperature of cooling air is 15-30 ℃, and the winding speed is 1500-2800 m/min.

9. Polyamide 56 filaments obtainable by the process according to any one of claims 1 to 8.

10. An apparatus for use in the process for producing a polyamide 56 filament as claimed in any one of claims 1 to 8, comprising: the device comprises a polymerization reaction device, a spinning forming device and a flexible post-processing device, wherein the polymerization reaction device is connected with the spinning forming device to directly prepare the polyamide 56 ultra-high-speed filament; then according to different demands of the market on products, connecting a flexible post-processing device, thereby preparing polyamide 56 filaments with different styles;

the polymerization reaction device consists of a raw material kettle, a salt forming kettle, a salt solution storage tank, a salt solution preparation tank, a salt solution intermediate tank, a concentration tank, a U-shaped reactor, a flash evaporator, a front polymerizer and a rear polymerizer which are connected in sequence;

the two raw material kettles are respectively a pentanediamine raw material kettle and an adipic acid raw material kettle;

the flexible post-processing device comprises a Fully Drawn Yarn (FDY) preparation device, a Draw Textured Yarn (DTY) preparation device and an Air Textured Yarn (ATY) preparation device, and specifically comprises the following steps:

the flexible post-processing device a consists of a drafting roller, a shaping device and a winding device which are connected in sequence and is used for preparing a fully drawn yarn process device;

the flexible post-processing device b consists of a drafting roller, a false twisting device, a network device, a shaping device, an oiling device and a winding device which are connected in sequence and is used for preparing a drawing textured yarn process device;

the flexible post-processing device c consists of a drawing roller, a cooling device, a jet texturing device and a winding device which are connected in sequence and is used for preparing an air textured yarn process device;